Romanian National Institute for Research and Development for Biological Sciences

Bucharest, Romania

Romanian National Institute for Research and Development for Biological Sciences

Bucharest, Romania
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Craciunescu O.,Romanian National Institute for Research and Development for Biological Sciences | Moldovan L.,Romanian National Institute for Research and Development for Biological Sciences | Moisei M.,Institute of Biochemistry of the Romanian Academy | Trif M.,Institute of Biochemistry of the Romanian Academy
Journal of Liposome Research | Year: 2013

Liposomes have the capacity to be used as efficient, biodegradable and nontoxic carriers of bioactive molecules and are able to better control their delivery at the site of interest. The objective of this study was to obtain and characterize an appropriate liposomal formulation of the bioactive molecule chondroitin sulfate (CS) for its use in the local treatment of inflammatory and degenerative disorders, specifically osteoarthritis (OA). Empty liposomes (L) and CS-entrapping liposomes (L-CS) were prepared by thin film hydration method followed by sonication and extrusion. They were characterized in terms of size, polydispersity index and ζ-potential by dynamic light scattering (DLS) and morphology by transmission electron microscopy. The effect of L-CS formulation on viability and morphology of mouse fibroblast cells and its biologic activity in hydrogen peroxide-stimulated cells were compared to those of L, non-encapsulated CS and a mixture of L and CS (L+CS). Our results demonstrated a high biocompatibility of L-CS and a more efficient cell protection against oxidative damage using L-CS treatment than CS or L+CS treatment. Also, L-CS exhibited a higher anti-inflammatory activity than CS in stimulated cells by reducing the level of IL-8 and TNF-α proinflammatory cytokines. The overall results suggest that the delivery of CS in liposomal formulation could improve its therapeutic potential in intra-articular treatment of OA. © 2013 Informa UK Ltd All rights reserved.


Paun A.,Louisiana Tech University | Paun A.,Romanian National Institute for Research and Development for Biological Sciences | Sidoroff M.,Romanian National Institute for Research and Development for Biological Sciences
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

In this paper we consider sequential SNP systems where the sequentiality of the system is induced by the max-spike: the neuron with the maximum number of spikes out of the neurons that can spike at one step will fire. This corresponds to a global view of the whole network that makes the system sequential. We continue the study in the direction of max-spike and show that systems with 132 neurons are universal. This improves a recent result in the area. © 2012 Springer-Verlag.


Diaconu M.,Romanian National Institute for Research and Development for Biological Sciences | Litescu S.C.,Romanian National Institute for Research and Development for Biological Sciences | Radu G.L.,Romanian National Institute for Research and Development for Biological Sciences
Microchimica Acta | Year: 2011

We are presenting a bienzymatic sensor for the determination of polyphenols. An ITO electrode was modified with multiwalled carbon nanotubes, and the enzymes laccase and tyrosinase were co-entrapped into a chitosan matrix. The resulting biosensor was calibrated at -50 mV (vs. the Ag/AgCl reference electrode) using rosmarinic acid, caffeic acid and gallic acid as the substrates. The new biosensor resulted in a 10.7-fold increase in response sensitivity and a considerable improvement of the detection limit (42 nM for rosmarinic acid). Fouling of the surface of the biosensor was prevented by applying the surfactant Tween 20. The data recorded in surfactant medium revealed a significant improvement of the operational stability and an enlarged linear concentration ranges (up to 12 μM for rosmarinic acid). The sensor was used to evaluate the total phenolic content from extracts of Salvia officinalis and cultures of Basilicum callus. © 2010 Springer-Verlag.


Gaspar A.,Romanian National Institute for Research and Development for Biological Sciences
Journal of medicine and life | Year: 2011

The aim of this study was to obtain four collagen based porous scaffolds and to assess their in vitro biocompatibility and biodegradability in order to use them for skin tissue engineering. We have prepared four variants of collagen-based biodegradable sponges by liophilization of type I collagen solution and three variants of collagen-agarose mixture in different ratios 2:1 (A), 1:1 (B) and 1:2 (C). These scaffolds had microporous structure with a higher than 98% porosity and a reduced biodegradation after their exposure to UV radiation. The incorporation of agarose into the collagen scaffolds has improved their structural stability. In vitro biocompatibility testing for the four types of sponges was performed on a stabilized fibroblast cell line and showed that both cell viability and morphology were not altered by collagen and collagen-agarose variants A and B sponges. These three porous sponges demonstrated potential for future application as cell scaffolds in skin tissue engineering.


Bucur B.,Romanian National Institute for Research and Development for Biological Sciences
Current Neuropharmacology | Year: 2012

In this paper is presented an overview of the technological barriers faced by the in vivo brain analysis with microelectrodes. Numerous microsensors and enzymatic microbiosensors have been developed for the real time monitoring of neurotransmitters, neuromodulators, drugs and diverse other biological relevant substances. A clear understanding of the working principle, advantages and limitations is essential for the acquisition of valid data in neurological investigations. Some of the aspects presented here refer to: microelectrode insertion and positioning related to possibilities to minimize tissue damage, spatial and temporal resolution of the measurements, actual controversies in data interpretation and sensor calibration, simultaneous detection of multiple analytes, interferences and state of the art in the development of wireless devices. © 2012 Bentham Science Publishers.


Litescu S.C.,Romanian National Institute for Research and Development for Biological Sciences
Advances in Experimental Medicine and Biology | Year: 2010

A comprehensive description of the most frequently used methods to determine the antioxidant activity in food and raw materials is given. The methods are classified into two categories, depending on the type of the assessment carried out. Several methods for the assessment of antioxidant efficacy using free radical scavenging such as Oxygen Radical Absorbance Capacity Assay (ORAC), Total Radical Trapping Antioxidant Parameter assay (TEAC), Ferric reducing antioxidant power assay (FRAP) and 2,2′-diphenyl- 1-picrylhydrazyl (DPPH) assay are described. An example of methods based on the assessment of antioxidant efficacy using significant biological substrates is also presented. Critical opinions concerning the proposed methods are presented. © 2010 Landes Bioscience and Springer Science+Business Media, LLC.


Litescu S.C.,Romanian National Institute for Research and Development for Biological Sciences
Advances in Experimental Medicine and Biology | Year: 2010

Antioxidants are groups of chemical substances, the most abundant being polyphenols, mainly found in plants, fruits and vegetables. They include flavonoids, flavonoid derivatives, polyphenols, carotenoids and anthocyanins. Currently, the nutritional quality of many foodstuffs is guaranteed by the presence of antioxidant compounds. The importance of these chemicals as indicators and preservatives of nutritional quality makes necessary the development of accurate, versatile and rapid analytical tools necessary to detect their presence in many foodstuffs and to assess their antioxidant efficacy. In this chapter, enzyme-based biosensors such as monophenol monooxygenase (tyrosinase), catechol oxidase (laccase) and horseradish peroxidase (HRP) are reviewed. Actually, these biosensors are the most commonly used for the detection of polyphenols and flavonoids content. © 2010 Landes Bioscience and Springer Science+Business Media, LLC.


Calugar A.,Romanian National Institute for Research and Development for Biological Sciences
Acarologia | Year: 2013

The present study analyzes the effects of pollution with cement powder on the Gamasina mite communities from soil organic horizon of some forest ecosystems. The study was carried out in two main polluted areas - one situated in Southern Romania (Cement Plant from Câmpulung Muscel - Arges County) and the other one in the North-East (the Tasca-Bicaz Cement Plant - Neamt County). Forest ecosystems located at different distances from the pollution sources were studied and the seasonal dynamics of both the gamasid fauna and community structures were monitored. The study focused on the suborder Gamasina Leach 1815, but the total abundance of the uropodids (Uropodina Kramer, 1882) was also considered. It was found that the percentage of Gamasina mites among all mites was higher in the control forests than in the polluted ecosystems, which was true for both polluted areas. Considering their ecological requirements, their habitat preference, vertical distribution in the soil, and seasonal population changes were investigated. In polluted biotopes, the Gamasina communities suffered from lower densities, fewer species and replacement of some species with others. The analysis of the Gamasina species distribution in the control and polluted ecosystems suggests that some species can be considered tolerant, such as certain representatives of Zerconidae, Parasitidae, Pachylaelapidae, Veigaiidae etc. © Cǎlugǎr A.


Stanciuc A.M.,Romanian National Institute for Research and Development for Biological Sciences
Roumanian archives of microbiology and immunology | Year: 2011

The aim of this study was to assess the antibacterial and antifungal potential of some Romanian medicinal plants, arnica--Arnica montana, wormwood--Artemisia absinthium and nettle--Urtica dioica. In order to perform this antimicrobial screening, we obtained the vegetal extracts and we tested them on a series of Gram-positive and Gram-negative bacteria, and also against two fungal strains. The vegetal extracts showed antimicrobial activity preferentially directed against the planktonic fungal and bacterial growth, while the effect against biofilm formation and development was demonstrated only against S. aureus and C. albicans. Our in vitro assays indicate that the studied plant extracts are a significant source of natural alternatives to antimicrobial therapy, thus avoiding antibiotic therapy, the use of which has become excessive in recent years.


Diaconu M.,Romanian National Institute for Research and Development for Biological Sciences | Litescu S.C.,Romanian National Institute for Research and Development for Biological Sciences | Radu G.L.,Romanian National Institute for Research and Development for Biological Sciences
Sensors and Actuators, B: Chemical | Year: 2010

Laccase from Trametes versicolor, an enzyme with broad substrate specificity for the phenolic substrates was employed as a biorecognition element in order to develop a biosensor for total content evaluation of phenolic secondary metabolites from two "in vitro" cultivated plants: Salvia officinalis and Mentha piperita. The enzyme immobilization was carried out by entrapment into the nanocomposite film during electrodeposition process from multiwall carbon nanotubes (MWCNT)-chitosan (CS) solution containing 25 U/mL laccase. Optimum conditions for MWCNT-CS film deposition (2 mg MWCNT/mL chitosan 1% solution prepared in 1% acetic acid) on gold support using a -1.5 V vs. Ag/AgCl controlled potential V for 5 min were established taking into consideration the layer capacity value. FTIR studies were performed to obtain information about the secondary structure of enzyme entrapped into the MWCNT-CS nanocomposite film. Calibration of the laccase biosensor was performed on four phenolic acids (caffeic acid, chlorogenic acid, gallic acids and rosmarinic acid) as substrates at -0.2 V vs. Ag/AgCl reference electrode. The developed biosensor was sensitive to micromolar concentration of the tested polyphenols. The performance characteristics of the biosensor for rosmarinic acid were: limit of detection 2.33 × 10-7 mol L-1, response linear range 9.1 × 10-7-1.21 × 10-5 mol L-1 and sensitivity 846 μA/mmol. The obtained values of the Kmapp for all tested substrates proved that nanocomposite film provides a proper environment for enzyme immobilization, preserving enzyme catalytic specificity. The functionality of the developed biosensor was tested to evaluate the total polyphenolic content from real samples (S. officinalis and M. piperita extracts), results being expressed in equivalent rosmarinic acid. © 2010 Elsevier B.V. All rights reserved.

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